Branched Chain Amino Acids (BCAAs) and Traumatic Brain Injury: A Systematic Review

Setting the Stage for Branched-Chain Amino Acids Use in Neurological Pathologies: Does a Single Oral Dose Provide Hours of Elevated Systemic Levels?

BACKGROUND

Recent studies have demonstrated that branched-chain amino acids are neuroprotective and neurorestorative. Branched-chain amino acid supplements are now being recommended to be taken before contact sports to reduce concussions. While peaks and troughs in branched-chain amino acids have previously been reported in hospital settings, the metabolism of a single recommended dose of over-the-counter branched-chain amino acids has yet to be elucidated.

METHODS

We analyzed a patented branched-chain amino acid product to assess its metabolism in 10 healthy adults.

RESULTS

Over the defined time points, measured levels of branched-chain amino acids remained significantly elevated when compared to the physiological baseline. The elevations in measured plasma levels indicate that a single oral dose is a viable intake option for increasing levels of branched-chain amino acids.

CONCLUSIONS

This information can be leveraged to better plan branched-chain amino acid-based treatment doses in order to treat pathologies such as brain injury.

The Role of Macronutrients and Gut Microbiota in Neuroinflammation Post-Traumatic Brain Injury: A Narrative Review

Traumatic brain injury (TBI) represents a multifaceted pathological condition resulting from external forces that disrupt neuronal integrity and function. This narrative review explores the intricate relationship between dietary macronutrients, gut microbiota (GM), and neuroinflammation in the TBI. We delineate the dual aspects of TBI: the immediate mechanical damage (primary injury) and the subsequent biological processes (secondary injury) that exacerbate neuronal damage. Dysregulation of the gut-brain axis emerges as a critical factor in the neuroinflammatory response, emphasizing the role of the GM in mediating immune responses. Recent evidence indicates that specific macronutrients, including lipids, proteins, and probiotics, can influence microbiota composition and in turn modulate neuroinflammation. Moreover, specialized dietary interventions may promote resilience against secondary insults and support neurological recovery post-TBI. This review aims to synthesize the current preclinical and clinical evidence on the potential of dietary strategies in mitigating neuroinflammatory pathways, suggesting that targeted nutrition and gut health optimization could serve as promising therapeutic modalities in TBI management.

Dietary Quality and Nutrient Intakes of Elite Paracyclists

Nutrient requirements for para-athletes will be influenced by a variety of factors secondary to their impairment and, therefore, recommendations for para-athletes cannot be drawn directly from that of able-bodied athletes. Information on the dietary intakes of para-athletes is lacking and therefore needs to be examined. This study assessed the nutrient intakes and diet quality of 31 paracyclists via food frequency questionnaires. Based on the dietary reference intakes, most paracyclists consumed intakes above the recommended dietary allowance (RDA) or adequate intake (AI). Recommendations were not met for iodine (males = 87% RDA; females = 62% RDA) or fibre in males (84% AI). A 26% risk of inadequacy was noted for vitamins D and E in females. A total of 42% of females and 75% of males did not meet fibre recommendations (14 g/1000 kcal), and only three athletes (all females) consumed fatty acids in the recommended omega-6 to omega-3 ratio of 4:1 or less. Athletes consumed grains, fruits, and vegetables frequently, though whole grains, pulses, and oily fish were generally consumed less often. Paracyclists appear to be consuming intakes at or above recommendations for most nutrients, though several nutrients were consumed below the recommended amounts; therefore, increasing the variety of foods consumed is suggested.

Complementary and Integrative Medicine in Treating Headaches, Cognitive Dysfunction, Mental Fatigue, Insomnia, and Mood Disorders Following Traumatic Brain Injury: A Comprehensive Review

Traumatic brain injury (TBI) is a complex condition associated with a range of persistent symptoms including headaches, cognitive dysfunction, mental fatigue, insomnia, and mood disorders. Conventional treatments for TBI-related symptoms can be insufficient, leading to interest in complementary and integrative medicine (CIM) approaches. This comprehensive article examines the existing literature on CIM modalities, including mind-body interventions, acupuncture/acupressure, herbal remedies, nutritional supplements, biofeedback, yoga, and tai chi in the context of managing secondary complications following TBI. The article highlights potential benefits and limitations of CIM modalities, while acknowledging the need for further research to better establish efficacy and safety in this specific population.

Time-Dependent Long-Term Effect of Memantine following Repetitive Mild Traumatic Brain Injury

Repetitive mild traumatic brain injury (rmTBI, e.g., sports concussions) may be associated with both acute and chronic symptoms and neurological changes. Despite the common occurrence of these injuries, therapeutic strategies are limited. One potentially promising approach is N-methyl-D-aspartate receptor (NMDAR) blockade to alleviate the effects of post-injury glutamatergic excitotoxicity. Initial pre-clinical work using the NMDAR antagonist, memantine, suggests that immediate treatment following rmTBI improves a variety of acute outcomes. It remains unclear (1) whether acute memantine treatment has long-term benefits and (2) whether delayed treatment following rmTBI is beneficial, which are both clinically relevant concerns. To test this, animals were subjected to rmTBI via a weight drop model with rotational acceleration (five hits in 5 days) and randomized to memantine treatment immediately, 3 months, or 6 months post-injury, with a treatment duration of one month. Behavioral outcomes were assessed at 1, 4, and 7 months post-injury. Neuropathological outcomes were characterized at 7 months post-injury. We observed chronic changes in behavior (anxiety-like behavior, motor coordination, spatial learning, and memory), as well as neuroinflammation (microglia, astrocytes) and tau phosphorylation (T231). Memantine treatment, either immediately or 6 months post-injury, appears to confer greater rescue of neuroinflammatory changes (microglia) than vehicle or treatment at the 3-month time point. Although memantine is already being prescribed chronically to address persistent symptoms associated with rmTBI, this study represents the first evidence of which we are aware to suggest a small but durable effect of memantine treatment in mild, concussive injuries. This effect suggests that memantine, although potentially beneficial, is insufficient to treat all aspects of rmTBI alone and should be combined with other therapeutic agents in a multi-therapy approach, with attention given to the timing of treatment.

Tracing the path of disruption: 13C isotope applications in traumatic brain injury-induced metabolic dysfunction

Cerebral metabolic dysfunction is a critical pathological hallmark observed in the aftermath of traumatic brain injury (TBI), as extensively documented in clinical investigations and experimental models. An in-depth understanding of the bioenergetic disturbances that occur following TBI promises to reveal novel therapeutic targets, paving the way for the timely development of interventions to improve patient outcomes. The 13C isotope tracing technique represents a robust methodological advance, harnessing biochemical quantification to delineate the metabolic trajectories of isotopically labeled substrates. This nuanced approach enables real-time mapping of metabolic fluxes, providing a window into the cellular energetic state and elucidating the perturbations in key metabolic circuits. By applying this sophisticated tool, researchers can dissect the complexities of bioenergetic networks within the central nervous system, offering insights into the metabolic derangements specific to TBI pathology. Embraced by both animal studies and clinical research, 13C isotope tracing has bolstered our understanding of TBI-induced metabolic dysregulation. This review synthesizes current applications of isotope tracing and its transformative potential in evaluating and addressing the metabolic sequelae of TBI.

Spatial amine metabolomics and histopathology reveal localized brain alterations in subacute traumatic brain injury and the underlying mechanism of herbal treatment

INTRODUCTION

Spatial changes of amine metabolites and histopathology of the whole brain help to reveal the mechanism of traumatic brain injury (TBI) and treatment.

METHODS

A newly developed liquid microjunction surface sampling-tandem mass tag-ultra performance liquid chromatography-mass spectrometry technique is applied to profile brain amine metabolites in five brain regions after impact-induced TBI at the subacute stage. H&E, Nissl, and immunofluorescence staining are performed to spatially correlate microscopical changes to metabolic alterations. Then, bioinformatics, molecular docking, ELISA, western blot, and immunofluorescence are integrated to uncover the mechanism of Xuefu Zhuyu decoction (XFZYD) against TBI.

RESULTS

Besides the hippocampus and cortex, the thalamus, caudate-putamen, and fiber tracts also show differentiated metabolic changes between the Sham and TBI groups. Fourteen amine metabolites (including isomers such as L-leucine and L-isoleucine) are significantly altered in specific regions. The metabolic changes are well matched with the degree of neuronal damage, glia activation, and neurorestoration. XFZYD reverses the dysregulation of several amine metabolites, such as hippocampal Lys-Phe/Phe-Lys and dopamine. Also, XFZYD enhances post-TBI angiogenesis in the hippocampus and the thalamus.

CONCLUSION

This study reveals the local amine-metabolite and histological changes in the subacute stage of TBI. XFZYD may promote TBI recovery by normalizing amine metabolites and spatially promoting dopamine production and angiogenesis.

The longitudinal biochemical profiling of TBI in a drop weight model of TBI

Traumatic brain injury (TBI) is a major cause of mortality and disability worldwide, particularly among individuals under the age of 45. It is a complex, and heterogeneous disease with a multifaceted pathophysiology that remains to be elucidated. Metabolomics has the potential to identify metabolic pathways and unique biochemical profiles associated with TBI. Herein, we employed a longitudinal metabolomics approach to study TBI in a weight drop mouse model to reveal metabolic changes associated with TBI pathogenesis, severity, and secondary injury. Using proton nuclear magnetic resonance (1H NMR) spectroscopy, we biochemically profiled post-mortem brain from mice that suffered mild TBI (N = 25; 13 male and 12 female), severe TBI (N = 24; 11 male and 13 female) and sham controls (N = 16; 11 male and 5 female) at baseline, day 1 and day 7 following the injury. 1H NMR-based metabolomics, in combination with bioinformatic analyses, highlights a few significant metabolites associated with TBI severity and perturbed metabolism related to the injury. We report that the concentrations of taurine, creatinine, adenine, dimethylamine, histidine, N-Acetyl aspartate, and glucose 1-phosphate are all associated with TBI severity. Longitudinal metabolic observation of brain tissue revealed that mild TBI and severe TBI lead distinct metabolic profile changes. A multi-class model was able to classify the severity of injury as well as time after TBI with estimated 86% accuracy. Further, we identified a high degree of correlation between respective hemisphere metabolic profiles (r > 0.84, p < 0.05, Pearson correlation). This study highlights the metabolic changes associated with underlying TBI severity and secondary injury. While comprehensive, future studies should investigate whether: (a) the biochemical pathways highlighted here are recapitulated in the brain of TBI sufferers and (b) if the panel of biomarkers are also as effective in less invasively harvested biomatrices, for objective and rapid identification of TBI severity and prognosis.

Traumatic brain injury, abnormal growth hormone secretion, and gut dysbiosis

The gut microbiome has been implicated in a variety of neuropathologies with recent data suggesting direct effects of the microbiome on host metabolism, hormonal regulation, and pathophysiology. Studies have shown that gut bacteria impact host growth, partially mediated through the growth hormone (GH)/insulin-like growth factor 1 (IGF-1) axis. However, no study to date has examined the specific role of GH on the fecal microbiome (FMB) or the changes in this relationship following a traumatic brain injury (TBI). Current literature has demonstrated that TBI can lead to either temporary or sustained abnormal GH secretion (aGHS). More recent literature has suggested that gut dysbiosis may contribute to aGHS leading to long-term sequelae now known as brain injury associated fatigue and cognition (BIAFAC). The aGHS observed in some TBI patients presents with a symptom complex including profound fatigue and cognitive dysfunction that improves significantly with exogenous recombinant human GH treatment. Notably, GH treatment is not curative as fatigue and cognitive decline typically recur upon treatment cessation, indicating the need for additional studies to address the underlying mechanistic cause.

Propranolol treatment during repetitive mild traumatic brain injuries induces transcriptomic changes in the bone marrow of mice

Introduction

There are 1.5 million new mild traumatic brain injuries (mTBI) annually in the US, with many of the injured experiencing long-term consequences lasting months after the injury. Although the post injury mechanisms are not well understood, current knowledge indicates peripheral immune system activation as a causal link between mTBI and long-term side effects. Through a variety of mechanisms, peripheral innate immune cells are recruited to the CNS after TBI to repair and heal the injured tissue; however, the recruitment and activation of these cells leads to further inflammation. Emerging evidence suggests sympathetic nervous system (SNS) activity plays a substantial role in the recruitment of immune cells post injury.

Methods

We sought to identify the peripheral innate immune response after repeated TBIs in addition to repurposing the nonselective beta blocker propranolol as a novel mTBI therapy to limit SNS activity and mTBI pathophysiology in the mouse. Mice underwent repetitive mTBI or sham injury followed by i.p. saline or propranolol. Isolated mRNA derived from femur bone marrow of mice was assayed for changes in gene expression at one day, one week, and four weeks using Nanostring nCounter® stem cell characterization panel.

Results

Differential gene expression analysis for bone marrow uncovered significant changes in many genes following drug alone, mTBI alone and drug combined with mTBI.

Discussion

Our data displays changes in mRNA at various timepoints, most pronounced in the mTBI propranolol group, suggesting a single dose propranolol injection as a viable future mTBI therapy in the acute setting.

Biological responses to terahertz radiation with different power density in primary hippocampal neurons

Terahertz (THz) radiation is a valuable imaging and sensing tool which is widely used in industry and medicine. However, it biological effects including genotoxicity and cytotoxicity are lacking of research, particularly on the nervous system. In this study, we investigated how terahertz radiation with 10mW (0.12 THz) and 50 mW (0.157 THz) would affect the morphology, cell growth and function of rat hippocampal neurons in vitro.

Acute metabolic alterations in the hippocampus are associated with decreased acetylation after blast induced TBI

INTRODUCTION

Blast induced Traumatic brain injury (BI-TBI) is common among military personnels as well as war affected civilians. In the war zone, people can also encounter repeated exposure of blast wave, which may affect their cognition and metabolic alterations.

OBJECTIVE

In this study we assess the metabolic and histological changes in the hippocampus of rats at 24 h post injury.

METHOD

Rats were divided into four groups: (i) Sham; (ii) Mild TBI (mi); (iii) Moderate TBI (mo); and (iv) Repetitive mild TBI (rm TBI) and then subjected to different intensities of blast exposure. Hippocampal tissues were collected after 24 h of injury for proton nuclear magnetic resonance spectroscopy (1H NMR spectroscopy) and immunohistochemical (IHC) analysis.

RESULTS

The metabolic alterations were found in the hippocampal tissue samples and these alterations showed significant change in glutamate, N-Acetylaspartic acid (NAA), acetate, creatine, phosphoethanolamine (PE), ethanolamine and PC/choline concentrations in rmTBI rats only. IHC studies revealed that AH3 (Acetyl histone) positive cells were decreased in rm TBI tissue samples in comparison to other TBI groups and sham rats. This might reflect an epigenetic alteration due to repeated blast exposure at 24 h post injury. Additionally, astrogliosis was observed in miTBI and moTBI hippocampal tissue while no change was observed in rmTBI tissues.

CONCLUSION

The present study reports altered acetylation in the presence of altered metabolism in hippocampal tissue of blast induced rmTBI at 24 h post injury. Mechanistic understanding of these intertwined processes may help in the development of better therapeutic pathways and agents for blast induced TBI in near future.

Association of sub-acute changes in plasma amino acid levels with long-term brain pathologies in a rat model of moderate-severe traumatic brain injury

Introduction

Traumatic brain injury (TBI) induces a cascade of cellular alterations that are responsible for evolving secondary brain injuries. Changes in brain structure and function after TBI may occur in concert with dysbiosis and altered amino acid fermentation in the gut. Therefore, we hypothesized that subacute plasma amino acid levels could predict long-term microstructural outcomes as quantified using neurite orientation dispersion and density imaging (NODDI).

Methods

Fourteen 8-10-week-old male rats were randomly assigned either to sham (n = 6) or a single moderate-severe TBI (n = 8) procedure targeting the primary somatosensory cortex. Venous blood samples were collected at days one, three, seven, and 60 post-procedure and NODDI imaging were carried out at day 60. Principal Component Regression analysis was used to identify time dependent plasma amino acid concentrations after in the subacute phase post-injury that predicted NODDI metric outcomes at day 60.

Results

The TBI group had significantly increased plasma levels of glutamine, arginine, alanine, proline, tyrosine, valine, isoleucine, leucine, and phenylalanine at days three-seven post-injury. Higher levels of several neuroprotective amino acids, especially the branched-chain amino acids (valine, isoleucine, leucine) and phenylalanine, as well as serine, arginine, and asparagine at days three-seven post-injury were also associated with lower isotropic diffusion volume fraction measures in the ventricles and thus lesser ventricular dilation at day 60.

Discussion

In the first such study, we examined the relationship between the long-term post-TBI microstructural outcomes across whole brain and the subacute changes in plasma amino acid concentrations. At days three to seven post-injury, we observed that increased plasma levels of several amino acids, particularly the branched-chain amino acids and phenylalanine, were associated with lesser degrees of ventriculomegaly and hydrocephalus TBI neuropathology at day 60 post-injury. The results imply that altered amino acid fermentation in the gut may mediate neuroprotection in the aftermath of TBI.

Nutritional interventions to support acute mTBI recovery

When mild traumatic brain injury (mTBI) occurs following an impact on the head or body, the brain is disrupted leading to a series of metabolic events that may alter the brain's ability to function and repair itself. These changes may place increased nutritional demands on the body. Little is known on whether nutritional interventions are safe for patients to implement post mTBI and whether they may improve recovery outcomes. To address this knowledge gap, we conducted a systematic review to determine what nutritional interventions have been prescribed to humans diagnosed with mTBI during its acute period (<14 days) to support, facilitate, and result in measured recovery outcomes.

Methods

Databases CINAHL, PubMed, SPORTDiscus, Web of Science, and the Cochrane Library were searched from inception until January 6, 2021; 4,848 studies were identified. After removing duplicates and applying the inclusion and exclusion criteria, this systematic review included 11 full papers.

Results

Patients that consumed enough food to meet calorie and macronutrient (protein) needs specific to their injury severity and sex within 96 h post mTBI had a reduced length of stay in hospital. In addition, patients receiving nutrients and non-nutrient support within 24-96 h post mTBI had positive recovery outcomes. These interventions included omega-3 fatty acids (DHA and EPA), vitamin D, mineral magnesium oxide, amino acid derivative N-acetyl cysteine, hyperosmolar sodium lactate, and nootropic cerebrolysin demonstrated positive recovery outcomes, such as symptom resolution, improved cognitive function, and replenished nutrient deficiencies (vitamin D) for patients post mTBI.

Conclusion

Our findings suggest that nutrition plays a positive role during acute mTBI recovery. Following mTBI, patient needs are unique, and this review presents the potential for certain nutritional therapies to support the brain in recovery, specifically omega-3 fatty acids. However, due to the heterogenicity nature of the studies available at present, it is not possible to make definitive recommendations.

Systematic review registration

The systematic review conducted following the PRISMA guidelines protocol was registered (CRD42021226819), on Prospero.

Branched-Chain Amino Acids Are Neuroprotective Against Traumatic Brain Injury and Enhance Rate of Recovery: Prophylactic Role for Contact Sports and Emergent Use

Branched-chain amino acids (BCAAs) are known to be neurorestorative after traumatic brain injury (TBI). Despite clinically significant improvements in severe TBI patients given BCAAs after TBI, the approach is largely an unrecognized option. Further, TBI continues to be the most common cause of morbidity and mortality in adolescents and adults. To date, no study has evaluated whether BCAAs can be preventive or neuroprotective if taken before a TBI. We hypothesized that if BCAAs were elevated in the circulation before TBI, the brain would readily access the BCAAs and the severity of injury would be reduced. Before TBI induction with a standard weight-drop method, 50 adult mice were randomized into groups that were shams, untreated, and pre-treated, post-treated, or pre- + post-treated with BCAAs. Pre-treated mice received BCAAs through supplemented water and were dosed by oral gavage 45 min before TBI induction. All mice underwent beam walking to assess motor recovery, and the Morris water maze assessed cognitive function post-injury. On post-injury day 14, brains were harvested to assess levels of astrocytes and microglia with glial fibrillary acidic protein (GFAP) and ionized calcium-binding adapter molecule 1 (IBA-1) immunohistochemistry, respectively. Pre-treated and pre- +post-treated mice exhibited significantly better motor recovery and cognitive function than the other groups. The pre- + post-treated group had the best overall memory performance, whereas the pre-treated and post-treated groups only had limited improvements in memory compared to untreated animals. Pre- + post-treated brains had levels of GFAP that were similar to the sham group, whereas the pre-only and post-only groups showed increases. Although trends existed, no meaningful changes in IBA-1 were detected. This is the first study, animal or human, to demonstrate that BCAA are neuroprotective and substantiates their neurorestorative benefits after TBI, most likely through the important roles of BCAAs to glutamate homeostasis.

Dietary Supplementation With Branched Chain Amino Acids to Improve Sleep in Veterans With Traumatic Brain Injury: A Randomized Double-Blind Placebo-Controlled Pilot and Feasibility Trial

Study Objectives

Traumatic brain injury (TBI) is associated with chronic sleep disturbances and cognitive impairment. Our prior preclinical work demonstrated dietary supplementation with branched chain amino acids (BCAA: leucine, isoleucine, and valine), precursors to de novo glutamate production, restored impairments in glutamate, orexin/hypocretin neurons, sleep, and memory in rodent models of TBI. This pilot study assessed the feasibility and preliminary efficacy of dietary supplementation with BCAA on sleep and cognition in Veterans with TBI.

Methods

Thirty-two Veterans with TBI were prospectively enrolled in a randomized, double-blinded, placebo-controlled trial comparing BCAA (30 g, b.i.d. for 21-days) with one of two placebo arms (microcrystalline cellulose or rice protein, both 30 g, b.i.d. for 21-days). Pre- and post-intervention outcomes included sleep measures (questionnaires, daily sleep/study diaries, and wrist actigraphy), neuropsychological testing, and blood-based biomarkers related to BCAA consumption.

Results

Six subjects withdrew from the study (2/group), leaving 26 remaining subjects who were highly adherent to the protocol (BCAA, 93%; rice protein, 96%; microcrystalline, 95%; actigraphy 87%). BCAA were well-tolerated with few side effects and no adverse events. BCAA significantly improved subjective insomnia symptoms and objective sleep latency and wake after sleep onset on actigraphy.

Conclusion

Dietary supplementation with BCAA is a mechanism-based, promising intervention that shows feasibility, acceptability, and preliminary efficacy to treat insomnia and objective sleep disruption in Veterans with TBI. A larger scale randomized clinical trial is warranted to further evaluate the efficacy, dosing, and duration of BCAA effects on sleep and other related outcome measures in individuals with TBI.

Clinical Trial Registration

[http://clinicaltrials.gov/], identifier [NCT03990909].

Temporal profile of serum metabolites and inflammation following closed head injury in rats is associated with HPA axis hyperactivity

INTRODUCTION

Closed head injury (CHI) causes neurological disability along with systemic alterations that can activate neuro-endocrine response through hypothalamic-pituitary-adrenal (HPA) axis activation. A dysregulated HPA axis function can lead to relocation of energy substrates and alteration in metabolic pathways and inflammation at the systemic level.

OBJECTIVES

Assessment of time-dependent changes in serum metabolites and inflammation after both mild and moderate CHI. Along with this, serum corticosterone levels and hypothalamic microglial response were observed.

METHODS

Rats underwent mild and moderate weight-drop injury and their serum and hypothalamus were assessed at acute, sub-acute and chronic timepoints. Changes in serum metabolomics were determined using high resolution NMR spectroscopy. Serum inflammatory cytokine, corticosterone levels and hypothalamic microglia were assessed at all timepoints.

RESULTS

Metabolites including lactate, choline and branched chain amino acids were found as the classifiers that helped distinguish between control and injured rats during acute, sub-acute and chronic timepoints. While, increased αglucose: βglucose and TMAO: choline ratios after acute and sub-acute timepoints of mild injury differentiated from moderate injured rats. The injured rats also showed distinct inflammatory profile where IL-1β and TNF-α levels were upregulated in moderate injured rats while IL-10 levels were downregulated in mild injured rats. Furthermore, injury specific alterations in serum metabolic and immunologic profile were found to be associated with hyperactive HPA axis, with consistent increase in serum corticosterone concentration post injury. The hypothalamic microglia showed a characteristic activated de-ramified cellular morphology in both mild and moderate injured rats.

CONCLUSION

The study suggests that HPA axis hyperactivity along with hypothalamic microglial activation led to temporal changes in the systemic metabolism and inflammation. These time dependent changes in the metabolite profile of rats can further strengthen the knowledge of diagnostic markers and help distinguish injury related outcomes after TBI.

Protective Effect of Amino Acids on the Muscle Injury of Aerobics Athletes after Endurance Exercise Based on CT Images

During the training process, the aerobics athletes gradually increase their technical movements, the appreciation of the movements has been gradually improved, and the injuries of the athletes themselves have also gradually become serious. Based on CT image analysis, we study the protective effect of amino acids on aerobics athletes' muscle injury after endurance exercise. There are three major substance metabolism disorders in patients with muscle sclerosis, which are mainly manifested as decreased glucose tolerance and insulin resistance. Some patients develop muscle-derived diabetes. At the same time, the synthesis of lipids such as cholesterol and apolipoproteins decreases, the production of ketone bodies increases and the body uses more ketones for energy. The BCAA/AAA factor refers to the branched-chain amino acid/aromatic amino acid (BCAA/AAA) value. In amino acid metabolism, plasma albumin decreased significantly, the ratio of amino acids was unbalanced, and BCAA/AAA decreased, which was more likely to induce muscular encephalopathy. Using computer tomography (CT) to study the protective effect of amino acids on muscle injury, 32 aerobics athletes were randomly divided into an intervention group (Ig) and a control group (CG), each with 16 people. After 64-slice spiral CT scanning of muscles and three-dimensional reconstruction, the intervention group and the control group participated in aerobic endurance training 3 weeks in advance to establish a muscle microinjury model. The intervention group took the preprepared BCAA, while the control group did not take it. After three weeks of training, there will be one hour and three hours of aerobics competition. We need to detect changes in blood glucose (BS), creatine kinase (SCK), lactate dehydrogenase (LD), alanine (ALA), and alanine aminotransferase (AA) before and after exercise and 1 hour after exercise and record AVS athletes' pain analysis table. We successfully established the muscle injury model, letting all athletes' VAS score in 6-8 points; after 1 hour of exercise, the measurement results were the same as those of 2 hours. Therefore, after endurance training, the blood glucose content of the intervention group gradually decreased and returned to the original level after 2 hours of exercise, while the control group was lower than the level of exercise after 2 hours of exercise; the content of alanine in the two groups decreased more after 2 hours of exercise; the results of serum creatine kinase in the intervention group were higher than those in the control group after exercise. In the intervention group, lactate dehydrogenase increased rapidly at 2 hours after exercise; the alanine aminotransferase in the intervention group increased after exercise, but there was no significant change in the control group. It is also concluded that the longer the exercise time and the more energy consumption, the more effective the branched-chain amino acids supplement will be. The obtained imaging data can provide a more intuitive and accurate basis for the scientific selection of athletes, and amino acids can promote the synthesis of hormones, accelerate the synthesis of proteins and other products, reduce the content of creatine kinase in the blood, and protect the rapid recovery of muscle damage.

Nutrition Management in Patients With Traumatic Brain Injury: A Narrative Review

Traumatic brain injury (TBI) is a major cause of long-term physical and psychological disability and death. In patients with TBI, undernutrition is associated with an increased mortality rate, more infectious complications, and worse neurologic outcomes. Therefore, timely and effective nutritional therapy is particularly crucial in the management of TBI to improve patients' prognoses. This narrative review summarizes the issues encountered in clinical practice for patients with neurotrauma who receive acute and post-acute in-patient rehabilitation services, and it comprehensively incorporates a wide range of studies, including recent clinical practice guidelines (CPGs), with the aim of better understanding the current evidence for optimal nutritional therapy focused on TBI patients. Recent CPGs were reviewed for 6 topics: 1) hypermetabolism and variation in energy expenditure in patients with TBI, 2) delayed gastric emptying and intolerance to enteral nutrition, 3) decision-making on the route and timing of access in patients with TBI who are unable to maintain volitional intake (enteral nutrition versus parenteral nutrition), 4) decision-making on the enteral formula (standard or immune-modulating formulas), 5) glycemic control, and 6) protein support. We also identified areas that need further research in the future.

Cerebrolysin restores balance between excitatory and inhibitory amino acids in brain following concussive head injury. Superior neuroprotective effects of TiO2 nanowired drug delivery

Concussive head injury (CHI) often associated with military personnel, soccer players and related sports personnel leads to serious clinical situation causing lifetime disabilities. About 3-4k head injury per 100k populations are recorded in the United States since 2000-2014. The annual incidence of concussion has now reached to 1.2% of population in recent years. Thus, CHI inflicts a huge financial burden on the society for rehabilitation. Thus, new efforts are needed to explore novel therapeutic strategies to treat CHI cases to enhance quality of life of the victims. CHI is well known to alter endogenous balance of excitatory and inhibitory amino acid neurotransmitters in the central nervous system (CNS) leading to brain pathology. Thus, a possibility exists that restoring the balance of amino acids in the CNS following CHI using therapeutic measures may benefit the victims in improving their quality of life. In this investigation, we used a multimodal drug Cerebrolysin (Ever NeuroPharma, Austria) that is a well-balanced composition of several neurotrophic factors and active peptide fragments in exploring its effects on CHI induced alterations in key excitatory (Glutamate, Aspartate) and inhibitory (GABA, Glycine) amino acids in the CNS in relation brain pathology in dose and time-dependent manner. CHI was produced in anesthetized rats by dropping a weight of 114.6g over the right exposed parietal skull from a distance of 20cm height (0.224N impact) and blood-brain barrier (BBB), brain edema, neuronal injuries and behavioral dysfunctions were measured 8, 24, 48 and 72h after injury. Cerebrolysin (CBL) was administered (2.5, 5 or 10mL/kg, i.v.) after 4-72h following injury. Our observations show that repeated CBL induced a dose-dependent neuroprotection in CHI (5-10mL/kg) and also improved behavioral functions. Interestingly when CBL is delivered through TiO₂ nanowires superior neuroprotective effects were observed in CHI even at a lower doses (2.5-5mL/kg). These observations are the first to demonstrate that CBL is effectively capable to attenuate CHI induced brain pathology and behavioral disturbances in a dose dependent manner, not reported earlier.

An Overview and Therapeutic Promise of Nutraceuticals against Sports-Related Brain Injury

Sports-related traumatic brain injury (TBI) is one of the common neurological maladies experienced by athletes. Earlier the term 'punch drunk syndrome' was used in the case TBI of boxers and now this term is replaced by chronic traumatic encephalopathy (CTE). Sports-related brain injury can either be short term or long term. A common instance of brain injury encompasses subdural hematoma, concussion, cognitive dysfunction, amnesia, headache, vision issue, axonopathy, or even death if remain undiagnosed or untreated. Further, chronic TBI may lead to pathogenesis of neuroinflammation and neurodegeneration via tauopathy, formation of neurofibrillary tangles, and damage to the blood-brain barrier, microglial, and astrocyte activation. Thus, altered pathological, neurochemical, and neurometabolic attributes lead to the modulation of multiple signaling pathways and cause neurological dysfunction. Available pharmaceutical interventions are based on one drug one target hypothesis and thereby unable to cover altered multiple signaling pathways. However, in recent time's pharmacological intervention of nutrients and nutraceuticals have been explored as they exert a multifactorial mode of action and maintain over homeostasis of the body. There are various reports available showing the positive therapeutic effect of nutraceuticals in sport-related brain injury. Therefore, in the current article we have discussed the pathology, neurological consequence, sequelae, and perpetuation of sports-related brain injury. Further, we have discussed various nutraceutical supplements as well as available animal models to explore the neuroprotective effect/ upshots of these nutraceuticals in sports-related brain injury.

Nutritional interventions to improve neurophysiological impairments following traumatic brain injury: A systematic review

Traumatic brain injury (TBI) accounts for significant global health burden. Effects of TBI can become chronic even following mild injury. There is a need to develop effective therapies to attenuate the damaging effects of TBI and improve recovery outcomes. This literature review using a priori criteria (PROSPERO; CRD42018100623) summarized 43 studies between January 1998 and July 2019 that investigated nutritional interventions (NUT) delivered with the objective of altering neurophysiological (NP) outcomes following TBI. Risk of bias was assessed for included studies, and NP outcomes recorded. The systematic search resulted in 43 of 3,748 identified studies met inclusion criteria. No studies evaluated the effect of a NUT on NP outcomes of TBI in humans. Biomarkers of morphological changes and apoptosis, oxidative stress, and plasticity, neurogenesis, and neurotransmission were the most evaluated NP outcomes across the 43 studies that used 2,897 animals. The risk of bias was unclear in all reviewed studies due to poorly detailed methodology sections. Taking these limitations into account, anti-oxidants, branched chain amino acids, and ω-3 polyunsaturated fatty acids have shown the most promising pre-clinical results for altering NP outcomes following TBI. Refinement of pre-clinical methodologies used to evaluate effects of interventions on secondary damage of TBI would improve the likelihood of translation to clinical populations.

The Use of Vitamins, Supplements, Herbs, and Essential Oils in Rehabilitation

The term, dietary supplement, refers to a broad category of products, including herbal or plant-based extracts, micronutrients, and food-based nutraceuticals. The use of supplements in clinical rehabilitation requires clear communication from patients and health care providers to understand the types of products used and their effects on health. Providers should distinguish between using micronutrient supplementation for therapeutic purposes and treatment of nutritional deficiency in patients with malnutrition syndromes. Evidence supports micronutrient and nutraceutical supplementation use to improve pain, functional status, and inflammation. There is little evidence on the use of herbal or plant-based extracts in therapeutic rehabilitation; larger studies are warranted.

Complete neural stem cell (NSC) neuronal differentiation requires a branched chain amino acids-induced persistent metabolic shift towards energy metabolism

Neural stem cell (NSC) neuronal differentiation requires a metabolic shift towards oxidative phosphorylation. We now show that a branched-chain amino acids-driven, persistent metabolic shift toward energy metabolism is required for full neuronal maturation. We increased energy metabolism of differentiating neurons derived both from murine NSCs and human induced pluripotent stem cells (iPSCs) by supplementing the cell culture medium with a mixture composed of branched-chain amino acids, essential amino acids, TCA cycle precursors and co-factors. We found that treated differentiating neuronal cells with enhanced energy metabolism increased: i) total dendritic length; ii) the mean number of branches and iii) the number and maturation of the dendritic spines. Furthermore, neuronal spines in treated neurons appeared more stable with stubby and mushroom phenotype and with increased expression of molecules involved in synapse formation. Treated neurons modified their mitochondrial dynamics increasing the mitochondrial fusion and, consistently with the increase of cellular ATP content, they activated cellular mTORC1 dependent p70S6 K1 anabolism. Global transcriptomic analysis further revealed that treated neurons induce Nrf2 mediated gene expression. This was correlated with a functional increase in the Reactive Oxygen Species (ROS) scavenging mechanisms. In conclusion, persistent branched-chain amino acids-driven metabolic shift toward energy metabolism enhanced neuronal differentiation and antioxidant defences. These findings offer new opportunities to pharmacologically modulate NSC neuronal differentiation and to develop effective strategies for treating neurodegenerative diseases.

Metabolomics analysis reveals perturbations of cerebrocortical metabolic pathways in the Pahenu2 mouse model of phenylketonuria

AIMS

Phenylketonuria (PKU), which is caused by mutations in the phenylalanine hydroxylase (PAH) gene, is one of the most common inherited diseases of amino acid metabolism. Phenylketonuria is characterized by an abnormal accumulation of phenylalanine and its metabolites in body fluids and brain tissues, subsequently leading to severe brain dysfunction. Various pathophysiological and molecular mechanisms underlying brain dysfunction in PKU have been described. However, the metabolic changes and their impacts on the function of cerebral cortices of patients with PKU remain largely unknown.

METHODS

We measured the levels of small molecule metabolites in the cerebrocortical tissues of PKU mice and wild-type control mice using liquid chromatography-mass spectrometry (LC-MS)-based metabolome analysis. Differential metabolites were further subjected to metabolic pathway and enrichment analysis.

RESULTS

Metabolome analysis revealed 35 compounds among 143 detected metabolites were significantly changed in PKU mice as compared to those in their wild-type littermates. Metabolic pathway and enrichment analysis of these differential metabolites showed that multiple metabolic pathways, including phenylalanine, tyrosine, and tryptophan biosynthesis; valine, leucine, and isoleucine biosynthesis; alanine, aspartate, and glutamate metabolism; purine metabolism; arginine and proline metabolism and methionine metabolism, were impacted in the cerebral cortices of PKU mice.

CONCLUSIONS

The data revealed that multiple metabolic pathways in cerebral cortices of PKU mice were disturbed, suggesting that the disturbances of the metabolic pathways might contribute to neurological or neurodevelopmental dysfunction in PKU, which could thus provide new insights into brain pathogenic mechanisms in PKU as well as mechanistic insights for better understanding the complexity of the metabolic mechanisms of the brain dysfunction in PKU.

Discovery and validation of temporal patterns involved in human brain ketometabolism in cerebral microdialysis fluids of traumatic brain injury patients

Background

Traumatic brain injury (TBI) is recognized as a metabolic disease, characterized by acute cerebral glucose hypo-metabolism. Adaptive metabolic responses to TBI involve the utilization of alternative energy substrates, such as ketone bodies. Cerebral microdialysis (CMD) has evolved as an accurate technique allowing continuous sampling of brain extracellular fluid and assessment of regional cerebral metabolism. We present the successful application of a combined hypothesis- and data-driven metabolomics approach using repeated CMD sampling obtained routinely at patient bedside. Investigating two patient cohorts (n = 26 and n = 12), we identified clinically relevant metabolic patterns at the acute post-TBI critical care phase.

Methods

Clinical and CMD metabolomics data were integrated and analysed using in silico and data modelling approaches. We used both unsupervised and supervised multivariate analysis techniques to investigate structures within the time series and associations with patient outcome.

Findings

The multivariate metabolite time series exhibited two characteristic brain metabolic states that were attributed to changes in key metabolites: valine, 4-methyl-2-oxovaleric acid (4-MOV), isobeta-hydroxybutyrate (iso-bHB), tyrosyine, and 2-ketoisovaleric acid (2-KIV). These identified cerebral metabolic states differed significantly with respect to standard clinical values. We validated our findings in a second cohort using a classification model trained on the cerebral metabolic states. We demonstrated that short-term (therapeutic intensity level (TIL)) and mid-term patient outcome (6-month Glasgow Outcome Score (GOS)) can be predicted from the time series characteristics.

Interpretation

We identified two specific cerebral metabolic patterns that are closely linked to ketometabolism and were associated with both TIL and GOS. Our findings support the view that advanced metabolomics approaches combined with CMD may be applied in real-time to predict short-term treatment intensity and long-term patient outcome.

In vivo assessment of increased oxidation of branched-chain amino acids in glioblastoma

Altered branched-chain amino acids (BCAAs) metabolism is a distinctive feature of various cancers and plays an important role in sustaining tumor proliferation and aggressiveness. Despite the therapeutic and diagnostic potentials, the role of BCAA metabolism in cancer and the activities of associated enzymes remain unclear. Due to its pivotal role in BCAA metabolism and rapid cellular transport, hyperpolarized ¹³C-labeled α-ketoisocaproate (KIC), the α-keto acid corresponding to leucine, can assess both BCAA aminotransferase (BCAT) and branched-chain α-keto acid dehydrogenase complex (BCKDC) activities via production of [1-¹³C]leucine or ¹³CO₂ (and thus H¹³CO₃⁻), respectively. Here, we investigated BCAA metabolism of F98 rat glioma model in vivo using hyperpolarized ¹³C-KIC. In tumor regions, we observed a decrease in ¹³C-leucine production from injected hyperpolarized ¹³C-KIC via BCAT compared to the contralateral normal-appearing brain, and an increase in H¹³CO₃⁻, a catabolic product of KIC through the mitochondrial BCKDC. A parallel ex vivo¹³C NMR isotopomer analysis following steady-state infusion of [U-¹³C]leucine to glioma-bearing rats verified the increased oxidation of leucine in glioma tissue. Both the in vivo hyperpolarized KIC imaging and the leucine infusion study indicate that KIC catabolism is upregulated through BCAT/BCKDC and further oxidized via the citric acid cycle in F98 glioma.

Effect of the route of nutrition and L-alanyl-L-glutamine supplementation in amino acids' concentration in trauma patients

PURPOSE

Our purpose was to assess the amino acids' (AAs) profile in trauma patients and to assess the effect of the route of nutrition and the exogenous ALA-GLN dipeptide supplementation on plasma AAs' concentration.

METHODS

This is a secondary analysis of a previous randomized controlled trial. On day 1 and day 6 after trauma, plasma concentration of 25 AAs was measured using reverse phase high-performance liquid chromatography. Results were analyzed in relation to the route of nutrition and supplementation of ALA-GLN dipeptide. Differences between plasma AAs' concentrations at day 1 and day 6 were evaluated using the Student's t test or Mann-Whitney-Wilcoxon test. One-way ANOVA and the Kruskal-Wallis test were used to compare groups. A two-sided p value less than 0.05 was considered statistically significant.

RESULTS

Ninety-eight patients were analyzed. Mean plasma concentrations at day 1 were close to the lower normal level for most AAs. At day 6 we found an increase in the eight essential AAs' concentrations and in 9 out of 17 measured non-essential AAs. At day 6 we found no differences in plasma concentrations for the sum of all AAs (p = .72), glutamine (p = .31) and arginine (p = .23) distributed by the route of nutrition. Administration of ALA-GLN dipeptide increased the plasma concentration of alanine (p = .004), glutamine (p < .001) and citrulline (p = .006).

CONCLUSIONS

We found an early depletion of plasma AAs' concentration which partially recovered at day 6, which was unaffected by the route of nutrition. ALA-GLN dipeptide supplementation produced a small increase in plasma levels of glutamine and citrulline.